Wood shaving machine

ABSTRACT

In a wood shaving machine there are provided two juxtaposed, axially parallel shaving heads and two vertically swingable feed troughs, one associated with each shaving head. The pivotal axis of each trough is associated with the trough end that is remote from the shaving heads. During operation, the feed troughs are swung in opposite phase; cutting takes place during the upward swing as the wood logs in the feed trough is urged against the associated shaving head.

United States Patent 1191 Schaefer Feb. 12, 1974 WOOD SHAVING MACHINE 2,570,926 10 1951 Elmendorf 144/176 x 7 3,101,756 8/1963 Schubert.. 144/176 [75] Inventor- Karl schaefe" NewBdmberg, 3,162,222 12 1964 Kirsten 144/162 Germany 2,951,519 9/1960 Erickson et 31.. 241/280 [73] Assigneez Machinenfabrik B. Maier KGq 2,703,206 3/1955 Lyall 241/282 X Brackwede, Germany 22 Filed: Nov. 3 71 Primary ExaminerD onald Schran [211 A l N 203 317 Attorney, Agent, or F1rmEdw1n E. Gre gg [30] Foreign Application Priority Data l l ABSTRACT Nov. 30, 1970 Germany 2058821 In a wood Shaving machine there are provided two juxtaposed, axially parallel shaving heads and two ver- [52] U.S. Cl 144/172, 241/280, 214414//238226, ticany swingable feed troughs one associated with I t Cl B27] each shaving head. The pivotal axis of each trough is 58 d 176 326 associated with the trough end that is remote from the 1 le 0 earc 1/ shaving heads. During operation, the feed troughs are swung in opposite phase; cutting takes place during the upward swing as the wood logs in the feed trough [56] UNITE EEEZZZZS SZEFENTS is urged against the associated shaving head.

416,961 12/1889 Smith et al 144/162 R 9 Claims, 8 Drawing Figures WOOD SHAVING MACHINE BACKGROUND OF THE INVENTION This invention relates to a machine for obtaining wood shavings or wood slices that are cut parallel or at an acute angle with respect to the direction of grain.

Known machines of the aforenoted type are provided with feed troughs which are disposed at approximately 45 with respect to the shaving head. In machines of this type the introduced log or logs slide by gravity downwardly in the direction of grain. The stationary shaving head is arranged substantially parallel to the grain direction, i.e., parallel to the length dimension of the feed trough. In order to effect sharing of the introduced logs, the feed trough is pressed against the shaving head in a direction direction normal to the axis of the latter and then fragments of the logs corresponding in length to that of the shaving knife are sliced off the log stack. Machines of this type, however, have substantial disadvantages particularly due to the fact that their quantity output is relatively small. Further, only relativelyshort logs may be utilized because, due to conditions imposed by the possibilities of feed, the feed trough-has a limited length of approximately 2 meters. Also, in machines of this type an automatic feed can be effected only with difficulty.

In other known machines of the aforenoted type the problem of the longitudinally limited feed trough is solved by providing a horizontal feed trough, the length of which is, in principle, not limited. The logs have to be deposited in the horizontal feed trough side by side with respect to the direction of feed and oriented parallel with the direction of grain. At the end of the feed trough the log stack has to be immobilized by means of a great number of clamping elements before the shaving head, supported on a carriage, moves transversely to the grain direction over the advanced log stack and thus slices off a log fragment that corresponds in length to that of the shaving knife. Subsequently, the knife head, as well as the clamping elements, has to be returned into its initial position. Only after the log stack periods, the output of the power means to which the shaving head is connected is not utilized.

OBJECT AND SUMMARY OF THE INVENTION It is an object of the invention to provide an improved machine of the aforenoted type in which the disadvantages set forth are eliminated and which is adapted to handle wood assortments of different kinds, qualities and lengths without the necessity of first cutting the logs to a determined length.

It is a further object of the invention to provide an improved machine in which the clamping elements for clamping the logs against the trough can be omitted.

Briefly stated, according to the invention there are provided two stationary or swingable shaving heads disposed in an axially parallel, juxtaposed relationship and with each shaving head there is associated a feed trough pivotable in a vertical plane about an axis adjacent that end of the feed trough that is remote from its associated shaving head. During operation of the machine, the two feed troughs are raised and lowered in opposite phase. The feed troughs are associated with clamping mechanisms as well as conveying means for the intermittent feed of the logs in the direction of the shaving heads. The log feed is effected alternatingly and always in that feed trough which momentarily is in its lowest position. Due to the alternating operation of the machine, at any given time one of the shaving heads is fully in engagement with the wood so that there is a continuous output flow of shavings or slices. While the logs in the one trough moving upwards are shaved, with respect to the other trough the following steps are taking place:

a. the trough is lowered from its uppermost position into its lowest position,

b. the logs are shifted by a length corresponding substantially to that of the length of the shaving head,

c. the trough is lifted upto a position in which the logs are just beginning to touch the shaving head, and

d. remains in waiting position until the period of shaving of the first trough has been finished. The control of those different steps can be accomplished by controlling elements known in the art.

It is an advantage of the aforeoutlined machine that instead of the functionally problematical clamping elements that work from above in the known machines, the log stack is held fixedly and pressed against the momentarily operating shaving head by a clamping or pressure assembly disposed below the feed troughs adjacent to the shaving heads. Those clamping or pressure assemblies each constitute a vertically shiftable trough-shaped block which in its uppermost position within the region of the width of the corresponding trough partly embraces the shaving head associated therewith leaving between the shaving head and the block a gap of only a few tenths of a millimetre. Each block substantially forms an elongation of the corresponding trough below the shaving head. Preferably the vertical shifting movement of each block is coupled with the vertical shifting movement at least of the end of the corresponding trough, e.g., by means of a bar link. At the instance when during the lifting movement the logs are touching the shaving head, the latter is starting and the logs between the shaving head and the block are positively kept in a fixed position, i.e., they are immobilized within the trough. Thus additional clamping devices close to the shaving head across the trough can be omitted and even short logs are fixedly kept in position during the shaving process, because clamping is accomplished by the shaving head itself. The pivotal axis of the feed troughs is preferably shiftable in a stepless manner. The cutting angle of the shaving knives in the shaving heads is determined by the height of the shaving heads with respect to the bed height of the momentarily operational feed trough and by the distance between the pivotal axes of the'feed troughs and the shaving heads. By varying these magnitudes the quality of the finished product (for example, chipboards or paper) may be favorably affected.

The invention will be better understood, as well as further objects and advantages become more apparent, from the ensuing specification of a preferred, although exemplary, embodiment taken in conjunction with the drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a schematic side elevational view of the preferred embodiment;

FIG. 2 is a schematic top plan view of the same embodiment;

FIG. 3 is a schematic sectional view taken along line IHIII of FIG. 1;

FIG. 4 is a schematic sectional view, slightly enlarged, taken along line IVIV of FIG. 1;

FIG. 5 is a diagrammatic elevation view of the embodiment shown in FIG. 1 to 4;

FIG. 6 is a diagrammatic elevation view of an alternative embodiment of the invention;

FIG. 7 is a diagrammatic elevation of a further alternative embodiment of the inventioni and FIG. 8 is a fragmentary schematic plan view of the invention showing a deflector for the logs.

DESCRIPTION OF THE PREFERRED EMBODIMENT Refering to the embodiment shown in FIGS. 1 to 4, the machine 1 for making wood shavings or wood slices comprises two shaving heads 2, 3 including shaving knives (not shown) and supported in a juxtaposed, axially parallel relationship. With each shaving head 2, 3 there is associated a respective feed trough 4 and 5, each swingable in a vertical plane and each joined at its end remote from the associated shaving head by a further, rigidly positioned feed trough 6 and 7, respectively. In each feed trough 4, 5, 6 and 7 there is disposed a conveyor belt 8 or 8' resp. Each conveyor belt 8 is driven intermittently by a ratchet drive 9 actuated by a hydraulic piston 9'. As can best be seen in FIG. 4, at each end of the troughs 4 and 5 hydraulically operable lifting devices 10 and 11 resp. are disposed which at their upper ends each carry a trough-shaped block 12 and 13 resp., each being in line with the corresponding trough 4 or 5 resp. Those blocks 12 and 13 carry bar links 14 which engage the bottom side of short extensions 15 and 16 of the troughs 4 and 5 resp. When block 12 or 13 is lifted, the end of the respective trough 4 or 5 will be carried along and lifted simultaneously. On the left hand side of FIG. 4 block 12 is shown in its lowest position, in which the logs 17 are shifted longitudinally by a length corresponding to the width d (FIG. 1) of the shaving heads 2 and 3. On the right hand side of FIG. 4 block 13 is being lifted and shown in an intermediate position, having just started shaving of the logs 18 in trough 5. In its uppermost position blocks 12 or 13 resp. are almost touching the respective shaving heads 2 or 3, leaving a gap between them of only a few tenths of millimetres. 19 designates fixed counter blades known per se. The two feed troughs 4 and S are swingable in a vertical plane into a position shown in broken lines in FIG. 1 about an axis disposed at those ends of the troughs 4, 5 which are remote from the shaving heads 2, 3. This is shown diagrammatically in FIG. 5 in which the line 20 represents the upper surface of the conveyor belts 8 in the troughs 4 or 5 resp. and line 21 the upper surface of the conveyor belts 8 in the troughs 6 or 7 resp. Troughs 4 and 5 are swung around pivot 22 as shown by the dashed line 20'.

Thus the conveyor belt 8 of each feed trough 4, 5 is collinear in its lowest position with the shaving knives of the shaving heads 2, 3. By virtue of this arrangement, at the beginning of the shaving operation (i.e., upon raising one of the feed troughs) there are first produced shavings which are cut parallel to the direction of grain. During the course of the progressive shaving of a log stack engaged by a shaving head, shavings are cut at an acute angle a which is the greatest at the end of the shaving operation. It is known that wood boards made of shavings cut parallel to the direction of grain have a high resistance to breakage due to bending and a high transversal strength when made of shavings cut at an acute angle with respect to the grain. Thus, a particularly high-quality wood board may be made of a stepless shaving mixture which, in turn, may be produced by the shaving machine as indicated hereinabove.

It may be noted that, for claritys sake, in the figures the angle a is shown in a rather exaggerated manner.

FIG. 6 shows a modification of the machine for the manufacture of shavings cut uniformly either parallel or at an acute angle a with respect to the direction of grain, the forces of the clamping mechanisms of the feed troughs are transmitted to the rotational axes of the shaving heads which in this embodiment are designed swingably about a pivot axle 23. The shaving knives of the shaving heads thus always assume the same orientation with respect to the grain direction. The aforenoted embodiment is somewhat more complex and expensive than the first embodiment having fixedly held shaving heads, but it is by far less expensive than known machines with horizontally movable shaving heads, because the path which the last-named shaving heads have to travel is substantially longer than the relatively short stroke of the machine designed according to the aforenoted modification. Further, known shaving machines having a horizontally displaceable shaving head require for this motion a separate reversing drive means, while the two shaving heads according to the invention are swung solely about a rotational axis by the clamping mechanisms of the feed troughs.

To avoid changing of the cutting angle during operation according to another embodiment shown diagrammatically in FIG. 7, hydraulic piston means 24 are provided by which each axle of the pivots 22 can be shifted parallel to itself. In this case the feed troughs 6 and 7 adjacent the feed troughs 4 and 5 resp. have to be risen accordingly.

As shown in FIG. 8 it is also feasible to arrange upstream of the feed troughs 6 and 7 a conveying mechanism in which the individual logs are advanced parallel to one another and transversely to the length dimension of the feed troughs.

This conveying mechanism comprises a conveyor belt 25 arranged upstream of the feed troughs dividing the longitudinally stacked log pieces into two series before their introduction into the feed troughs. This division is performed by means of a wedge-shaped vertical dividing wall 26 which may be provided with deflector rollers or similar deflecting means to prevent an abutting of the advancing wood against the middle of the wedge and its subsequent transverse orientation. The wedge-shaped dividing wall 26 should supply the two feed troughs with approximately identical wood quantities.

According to a further embodiment of the conveying mechanism arranged upstream of the feed troughs, behind the wedge-shaped partition wall viewed in the direction of wood feed there are provided laterally upwardly swinging guide elements which may apply a resilient pressure and which thus shape the two wood series into a configuration of substantially quadratic cross section.

That which is claimed is:

l. A wood shaving machine comprising A. two axially parallel, juxtapositioned shaving heads each having rotary shaving knives,

B. a feed trough associated with each shaving head and having 1. a first end disposed adjacent its associated shaving head,

2. a second end remote from its associated shaving head,

C. conveying means disposed in each feed trough for advancing wood pieces towards said shaving heads,

D. clamping means associated with each feed trough adjacent said first end to immobilize the wood pieces therein,

E. means for vertically reciprocating said feed troughs below said shaving heads in opposite phase and 1 F. means for intermittently advancing said wood pieces on said conveying means, the advancing of said wood pieces taking place when each feed trough is in its lowest position during reciprocation.

2. A wood shaving machine as defined in claim 1, including a sole motor for driving said shaving heads.

3. A wood shaving machine as defined in claim 1, including means for so timing the motion of said feed troughs that at any given time one of said shaving heads is performing a cutting operation.

4. A wood shaving machine as defined in claim 1, including A. pivotal means connected to each second end for vertically swingably supporting each said feed trough and B. means for holding said shaving heads stationary to effect a relative movement between the feed trough and its associated shaving head during cutting to continuously vary, during the cutting operation, the cutting angle with respect to the direction of grain.

5. A wood shaving machine as defined in claim 4,

wherein said angle varies steplessly from 0 to 5.

6. A wood shaving machine as defined in claim 1, including means for swinging each shaving head about an axis passing through the center thereof for orienting each shaving head in such a manner during the vertical reciprocation of said feed tr'oughs that the cutting angle with respect to the direction of grain remains constant during the cutting operation.

7. A wood shaving machine as defined in claim 4, including means for steplessly shifting each said pivotal means during cutting operation for maintaining the cutting angle with respect to the direction of the wood grain at a constant value.

8. A wood shaving machine as defined in claim 1, including a conveying mechanism disposed upstream of said feed troughs, said conveying mechanism being collinear with each feed trough in at least one position thereof.

9. A wood shaving machine as defined in claim 8, said conveying mechanism disposed upstream of said feed troughs having a wedge-like upwardly sloping vertical control dividing wall. 

1. A wood shaving machine comprising A. two axially parallel, juxtapositioned shaving heads each having rotary shaving knives, B. a feed trough associated with each shaving head and having
 1. a first end disposed adjacent its associated shaving head,
 2. a second end remote from its associated shaving head, C. conveying means disposed in each feed trough for advancing wood pieces towards said shaving heads, D. clamping means associated with each feed trough adjacent said first end to immobilize the wood pieces therein, E. means for vertically reciprocating said feed troughs below said shaving heads in opposite phase and F. means for intermittently advancing said wood pieces on said conveying means, the advancing of said wood pieces taking place when each feed trough is in its lowest position during reciprocation.
 2. a second end remote from its associated shaving head, C. conveying means disposed in each feed trough for advancing wood pieces towards said shaving heads, D. clamping means associated with each feed trough adjacent said first end to immobilize the wood pieces therein, E. means for vertically reciprocating said feed troughs below said shaving heads in opposite phase and F. means for intermittently advancing said wood pieces on said conveying means, the advancing of said wood pieces taking place when each feed trough is in its lowest position during reciprocation.
 2. A wood shaving machine as defined in claim 1, including a sole motor for driving said shaving heads.
 3. A wood shaving machine as defined in claim 1, including means for so timing the motion oF said feed troughs that at any given time one of said shaving heads is performing a cutting operation.
 4. A wood shaving machine as defined in claim 1, including A. pivotal means connected to each second end for vertically swingably supporting each said feed trough and B. means for holding said shaving heads stationary to effect a relative movement between the feed trough and its associated shaving head during cutting to continuously vary, during the cutting operation, the cutting angle with respect to the direction of grain.
 5. A wood shaving machine as defined in claim 4, wherein said angle varies steplessly from 0* to 5*.
 6. A wood shaving machine as defined in claim 1, including means for swinging each shaving head about an axis passing through the center thereof for orienting each shaving head in such a manner during the vertical reciprocation of said feed troughs that the cutting angle with respect to the direction of grain remains constant during the cutting operation.
 7. A wood shaving machine as defined in claim 4, including means for steplessly shifting each said pivotal means during cutting operation for maintaining the cutting angle with respect to the direction of the wood grain at a constant value.
 8. A wood shaving machine as defined in claim 1, including a conveying mechanism disposed upstream of said feed troughs, said conveying mechanism being collinear with each feed trough in at least one position thereof.
 9. A wood shaving machine as defined in claim 8, said conveying mechanism disposed upstream of said feed troughs having a wedge-like upwardly sloping vertical control dividing wall. 